Labview writing incorrect DIO port in USB 8451

[vedsoni1996]

There are 8 ports on the 8451 p0.0 to p0.7. I'm trying to control multiple relays, hence I'm using multiple ports. If i use multiple lines in one port, then I'll have to code for all the bits in a line every time I have to send a signal to only one relay, which might make stuff complicated.

[crossrulz · Accepted solution]

---

@vedsoni1996 wrote:

There are 8 ports on the 8451 p0.0 to p0.7.

---

Wrong!  That is 1 port (P0) with 8 lines (0 - 7).

---

@vedsoni1996 wrote:

If i use multiple lines in one port, then I'll have to code for all the bits in a line every time I have to send a signal to only one relay, which might make stuff complicated.

---

Wrong again.  You use the Write Digital Line like I showed in my previous post.

It sounds like what you really want is something like the USB-6509, which has 12 digital ports (P0 to P11), 8 lines per port, adding up to 96 individual lines.  And,yes, you can create a separate task at the line or the port level.  So control of your individual relays would still be simple.

[vedsoni1996]

Okay.. Thanks a lot! I'll code using the write line command.

[alexela]

Hey, did you managed to make it work? 

Having same problem.

If you did, could you please send VI?

Thanks

[vedsoni1996]

Hey!

I cannot send you the VI, but here's a picture of the same:

Basically, there's only 1 port with 8 lines (0 - 7) on the NI 8451, so keep the port number unconnected and set the line number to what you want.

[alexela]

For some reason i can read values but cannot write.

Tried whole day. Not working (

Even simple LED connection not working. 

[vedsoni1996]

Refer to the image in my previous post. For writing values, you need to set the Logic Value control to FALSE, I guess. Try changing it from 0/1 and see what happens. Best thing is to refer to NI 8451 user manual.

[vedsoni1996]

Just saw your image. Why have you put the writing part inside an infinite while loop?

Your while loop will never stop if you've set FALSE as a stopping condition. I'd say remove the while loop.

And as I said before, try changing the value of the boolean. Also, these are the properties I set in my NI-845x device configuration:

Try using these.